Native Leeches.

Star (Christchurch), Volume XLIV, Issue 578, 7 October 1932, Page 6

Native Leeches.

Nature Notes

By

James Drummond, F.L.S., F.Z.S.

f)N OPEN BAY ISLAND, off the coast of W South Westland, Mr W. Dunlop searched for wetas, ugly insects called Maori devils, in burrows made by mutton-birds in moist earth on a hillside. While plucking up tufts of grass and groping amongst the roots, embedded .in swampy soil, he felt a bite on his wrist. On carefully withdrawing his hand, he found that a leech had attached itself to his skin. Investigation disclosed six more leeches and several cocoons.

These New Zealand leeches are not the same species as the medicinal leech of Europe, Ilirudo medicinalis, but are allied to it. The medicinal leech once was used largely for blood-letting. In cultivating it, an important industry was established in Europe and in the British Isles. Extensive swamps in France were amongst the chief sources of supplies. Old horses and cattle were driven into enclosures to provide the leeches with food. They were caught by peasants, who waded into shallow water until the leeches fixed themselves to the people’s bare legs. It is estimated that at one time 30.000.000 leeches were used medicinally in England and France every year. A single hatchery near Hildesheim, Germany, raised 3,500,000 in one The horse-leech, Aulostoma gulo, belongs to another genus. It is voracious, but hardly is as black as it is painted. A belief that nine horse-leeches will suck a horse to death is founded on nothing more substantial than imagination. Neither the medicinal leech nor the horse-leech has been found in New Zealand.